1. Field of the Invention
This invention relates generally to document storage and retrieval systems and more particularly to a method of indexing documents so that they can be retrieved in response to a query in order of their relevance to the query. It also permits, general query to be easily modified based on the content of the documents so that the new query will retrieve documents that are relevant to the original query.
2. Description of the Prior Art
Document retrieval based on indexing of the documents in a document data base is well known. Typically the documents are indexed by creating an index file which records the documents that each word is in. Then when the user inputs a query, the documents that contain one or more words of the query can be quickly identified. However, if the query consists of general words that are not terms of art, the query may produce unsatisfactory retrieval results by either producing few documents that are of interest to the user or producing many documents that are not interesting to the user or both.